Echinacea stirs up the immune system

Sometime in the late 19th century, both Europeans and North Americans realized that the herb echinacea was a medicinal gift from nature. In 1919, noted anthropologist Melvin Gilmore remarked in a study of the Plains Indians that “echinacea seems to have been used as a remedy for more ailments than any other plant.” A member of the sunflower family, echinacea remains a popular herb. Nine species are found in North America, but only three (E. pallida, E. angustifolia and E. purpurea) have been found to have healing properties.

Uses: Echinacea’s roots, leaves and flowers were used by Indians for bee stings and snake bites. Contemporary use of the herb has focused on its ability to stimulate the immune system.

Dose: In tablet form, typically 1,000 milligrams a day.

Precautions: Echinacea could interfere with drugs used to suppress the immune system, such as those used by people who have had organ transplants. People with HIV also should avoid the herb because stimulating the immune system may stimulate the virus. People with lupus, in which the immune system doesn’t function properly, shouldn’t take echinacea because stimulating the immune system could aggravate the condition. Allergic reactions to echinacea are possible, especially among people with ragweed allergies.

Research: Studies of echinacea’s effects on the common cold have been mixed. That could be because preparations vary widely, and researchers don’t know which species, and which parts of the plant, are superior. A government study is addressing that question. Another study is examining whether echinacea given to children ages 2 to 11 shortens the duration of upper respiratory infections and prevents bacterial infections.

Dietary supplement makers are not required by the U.S. government to demonstrate that their products are safe or effective. Ask your health-care provider for advice on selecting a brand.